When my server is sitting idle (to me) but I see in Webmin that there are 1500+ running processes, how can I determine which processes are necessary and which ones should be killed? Is this possibly a virus or some related type of hijacking of my system? If I plug a monitor into the server itself, I...

I upgraded my headless server to 11.04 from 10.04 (server version) and it seems I got a whole bunch of packages that I didn't previously have. Now my 8GB SSD where the OS resides is almost full. Previously it was using less than 1GB. I'm not too familiar with what all the packages are for, and I've ...